This invention generally relates to track laying vehicles and more particularly to suspensions for tracked vehicles such as, for example, snowmobiles and the like.
In the suspension of tracked vehicles, bogie wheel as well as slide-type suspensions or combinations thereof, are generally well known and used in the industry. A bogie wheel suspension is costly by virtue of the number and complexity of mechanical parts and is an inefficient system in deep snow due to the high rolling resistance of the small bogie wheels. A slide suspension is less costly than the bogie wheel suspension and is more efficient in deep snow giving more support and stability to the vehicle, but it must have snow for a lubricant and for cooling of the rub surfaces between the slide rail and track. Therefore, it is not suitable for use on ice, hard-packed snow, or where dry ground conditions exist. Furthermore, the track must be configured with rub surfaces, such as for example, metal clips and the like, to lower the coefficient of friction between the track and the slide. Such modifications to the track naturally increase its cost.
These and other factors and influences have been limitations to the useful operational range of this type vehicle and it is, therefore, a primary object of the instant invention to provide a suspension for tracked vehicles that is operationally simple, easily adapted to presently designed vehicles and is not limited by a lack of snow or other lubrication or by the operating conditions. Still another object is to provide a suspension that allows for the use of a much simplified track having no requirement for embedded metal slide surfaces and the like.
In its broad aspect, the invention envisions a belt-type suspension wherein one or more belts are supported by one or more pulleys, which belt or belts operate in conjunction with the vehicle track to hold the track to the ground as it rolls over the terrain. More specifically, the invention provides a belt-type suspension that is mounted in a relative position to the track, on its inside pathway between the track drive and adjusting pulleys and in engagement with the track to run at the same speed as the track. Belts of the type alluded to that may be applied to the suspension that is the subject of this invention are described in a copending application Ser. No. 944,485 filed concurrently herewith and entitled, Anti-Backbend Belts. The teaching of said application is incorporated by reference herein and the subject belts may be applied to the suspension of this invention when an anti-backbend characteristic is required, as will be more fully appreciated from the detailed description that follows.